Fathom looks a lot like Beneel but with more fins and a larger appearance. It has three fins with pink flipper like fins on it, also it has blue skin, and a light blueish gray underbelly; it has pink eyes and a pink tail. Its head is a different shade of blue and its middle body has dark blue stripe. And lastly the front fin has white dots.
"Fathoms are the largest known monster at the Academy. They rarely surface from the ocean depths, returning only to watch passing ships."
- Fathom is a form of measurement used in the water, equating to 6 feet.
There is a world, Oceanus, named after Fathom.